[vb.net] Resizing Images in VB.NET

I'd like to make a simple VB utility to resize images using vb.net. I am having trouble figuring out what vb class to use to actually manipulate the images. The Image class and the Bitmap class don't work.

Any ideas, hints, tips, tutorial links are greatly appreciated.

Thanks.

You can simply use this one line code to resize your image in visual basic .net

Public Shared Function ResizeImage(ByVal InputImage As Image) As Image
        Return New Bitmap(InputImage, New Size(64, 64))
End Function

Where;

1. "InputImage" is the image you want to resize.
2. "64 X 64" is the required size you may change it as your needs i.e 32X32 etc.

    Dim x As Integer = 0
    Dim y As Integer = 0
    Dim k = 0
    Dim l = 0
    Dim bm As New Bitmap(p1.Image)
    Dim om As New Bitmap(p1.Image.Width, p1.Image.Height)
    Dim r, g, b As Byte
    Do While x < bm.Width - 1
        y = 0
        l = 0
        Do While y < bm.Height - 1
            r = 255 - bm.GetPixel(x, y).R
            g = 255 - bm.GetPixel(x, y).G
            b = 255 - bm.GetPixel(x, y).B
            om.SetPixel(k, l, Color.FromArgb(r, g, b))
            y += 3
            l += 1
        Loop
        x += 3
        k += 1
    Loop
    p2.Image = om

This is basically Muhammad Saqib's answer except two diffs:

1: Adds width and height function parameters.

2: This is a small nuance which can be ignored... Saying 'As Bitmap', instead of 'As Image'. 'As Image' does work just fine. I just prefer to match Return types. See Image VS Bitmap Class.

Public Shared Function ResizeImage(ByVal InputBitmap As Bitmap, width As Integer, height As Integer) As Bitmap
    Return New Bitmap(InputImage, New Size(width, height))
End Function

Ex.

Dim someimage As New Bitmap("C:\somefile")
someimage = ResizeImage(someimage,800,600)

This will re-size any image using the best quality with support for 32bpp with alpha. The new image will have the original image centered inside the new one at the original aspect ratio.

#Region " ResizeImage "
    Public Overloads Shared Function ResizeImage(SourceImage As Drawing.Image, TargetWidth As Int32, TargetHeight As Int32) As Drawing.Bitmap
        Dim bmSource = New Drawing.Bitmap(SourceImage)

        Return ResizeImage(bmSource, TargetWidth, TargetHeight)
    End Function

    Public Overloads Shared Function ResizeImage(bmSource As Drawing.Bitmap, TargetWidth As Int32, TargetHeight As Int32) As Drawing.Bitmap
        Dim bmDest As New Drawing.Bitmap(TargetWidth, TargetHeight, Drawing.Imaging.PixelFormat.Format32bppArgb)

        Dim nSourceAspectRatio = bmSource.Width / bmSource.Height
        Dim nDestAspectRatio = bmDest.Width / bmDest.Height

        Dim NewX = 0
        Dim NewY = 0
        Dim NewWidth = bmDest.Width
        Dim NewHeight = bmDest.Height

        If nDestAspectRatio = nSourceAspectRatio Then
            'same ratio
        ElseIf nDestAspectRatio > nSourceAspectRatio Then
            'Source is taller
            NewWidth = Convert.ToInt32(Math.Floor(nSourceAspectRatio * NewHeight))
            NewX = Convert.ToInt32(Math.Floor((bmDest.Width - NewWidth) / 2))
        Else
            'Source is wider
            NewHeight = Convert.ToInt32(Math.Floor((1 / nSourceAspectRatio) * NewWidth))
            NewY = Convert.ToInt32(Math.Floor((bmDest.Height - NewHeight) / 2))
        End If

        Using grDest = Drawing.Graphics.FromImage(bmDest)
            With grDest
                .CompositingQuality = Drawing.Drawing2D.CompositingQuality.HighQuality
                .InterpolationMode = Drawing.Drawing2D.InterpolationMode.HighQualityBicubic
                .PixelOffsetMode = Drawing.Drawing2D.PixelOffsetMode.HighQuality
                .SmoothingMode = Drawing.Drawing2D.SmoothingMode.AntiAlias
                .CompositingMode = Drawing.Drawing2D.CompositingMode.SourceOver

                .DrawImage(bmSource, NewX, NewY, NewWidth, NewHeight)
            End With
        End Using

        Return bmDest
    End Function
#End Region

Don't know much VB.NET syntax but here's and idea

Dim source As New Bitmap("C:\image.png") 
Dim target As New Bitmap(size.Width, size.Height, PixelFormat.Format24bppRgb)

Using graphics As Graphics = Graphics.FromImage(target)
    graphics.DrawImage(source, new Size(48, 48)) 
End Using